Theory and simulation of short-range models of globular protein solutions

TL;DR

This paper combines theoretical modeling and simulations to understand phase behavior in globular protein solutions, demonstrating that simple short-range interaction models can accurately reproduce experimental phase diagrams.

Contribution

It introduces a DLVO-like model fitted to experimental data that successfully predicts phase coexistence and crystallization in protein solutions.

Findings

Model reproduces experimental phase diagrams

Phase behavior depends on ionic strength

Minimal assumptions suffice for accurate predictions

Abstract

We report theoretical and simulation studies of phase coexistence in model globular protein solutions, based on short-range, central, pair potential representations of the interaction among macro-particles. After reviewing our previous investigations of hard-core Yukawa and generalised Lennard-Jones potentials, we report more recent results obtained within a DLVO-like description of lysozyme solutions in water and added salt. We show that a one-parameter fit of this model based on Static Light Scattering and Self-Interaction Chromatography data in the dilute protein regime, yields demixing and crystallization curves in good agreement with experimental protein-rich/protein-poor and solubility envelopes. The dependence of cloud and solubility points temperature of the model on the ionic strength is also investigated. Our findings highlight the minimal assumptions on the properties of the microscopic interaction sufficient for a satisfactory reproduction of the phase diagram topology of globular protein solutions.